The following United States patent applications, which were concurrently filed with this one on Oct. 28, 1999, are fully incorporated herein by reference: Method and System for Navigating a Catheter Probe in the Presence of Field-influencing Objects, by Michael Martinelli, Paul Kessman and Brad Jascob; Patient-shielding and Coil System, by Michael Martinelli, Paul Kessman and Brad Jascob; Navigation Information Overlay onto Ultrasound Imagery, by Paul Kessman, Troy Holsing and Jason Trobaugh; Coil Structures and Methods for Generating Magnetic Fields, by Brad Jascob, Paul Kessman and Michael Martinelli; Registration of Human Anatomy Integrated for Electromagnetic Localization, by Mark W. Hunter and Paul Kessman; System for Translation of Electromagnetic and Optical Localization Systems, by Mark W. Hunter and Paul Kessman; and Surgical Communication and Power System, by Mark W. Hunter, Paul Kessman and Brad Jascob.
1. Field of the Invention
The present invention relates to a surgical sensor which may be integrated with an anatomical anchor. The sensor has particular applicability in surgical procedures where it is desirable to track the relative movement of one or more structures.
2. Description of the Related Art
Many surgical procedures are planned and guided using images obtained from imaging systems such as magnetic resonance imagers (MRIs), computer tomographic imagers (CTs), x-ray imagers, position emission tomographic (PET) scanners, and photo-emission computer technology (SPECT). These systems permit physicians to obtain detailed preoperative (or intraoperative) views of anatomical structures using noninvasive procedures. Once these images are obtained, the physician typically uses the images to plan a corrective surgical procedure. With the patient lying on an operating table, the images may be xe2x80x9cregisteredxe2x80x9d with the corresponding physical space of the patient, and displayed on a screen in the operating room (OR). As the physician navigates probes or other medical instruments within the patient, sensors on the instruments relay positional information to a computer. The computer, in turn, overlays a display of the position of the instrument on the image of the anatomical structure. In this way, the physician may navigate through a surgical procedure by viewing a display screen in the OR. An example of a related art system is found in U.S. patent application Ser. No. 08/809,404, entitled: xe2x80x9cSurgical Navigation System Including Reference and Localization Frame,xe2x80x9d and which is fully incorporated herein by reference.
Until now, the tracking of anatomical structures has been largely limited to external tracking, either by taping a sensor to a patient""s skin, or by affixing an external clamp to the patient, such as a Mayfield clamp, attached externally to a patient""s head.
U.S. patent application Ser. No. 08/931,654 entitled Bone Navigation System which is incorporated fully herein by reference discloses a system which employs screws extending from a bone fragment through a patient""s skin and connected to a platform external to the patient. Tracking elements such as, for example, emitters are located on the platform so that when a bone fragment moves, so too does the platform with the connected tracking elements. An array in the OR tracks movement of the tracking elements, and this movement is correlated to the movement of the bone fragment, in order to precisely track the movement of the bone fragment. Alternatively, clamps may be used, in place of screws, to secure an array of tracking elements to a bone structure. While such related art systems may generally be reliable, their structure is somewhat cumbersome, especially when the movement of multiple anatomical structures needs to be tracked. In addition, the use of the tracking elements and receiving array requires an unobstructed line of sight therebetween which not only limits implantation within a patient, but also can lead to interference.
For these reasons, in procedures such as those involving the spine or the reconstruction or repair of vertebral bodies, fractured skulls, fragmented bones, or other damaged boney structures, it has been somewhat difficult to track the relative movement of multiple anatomical structures.
It is an object of certain aspects of this invention to enable the detection of anatomical structure movement during medical procedures without the use of cumbersome external equipment fixed to the patient.
It is another object of certain aspects of the invention to provide a localization system for internal and/or external anatomical structures that do not require an unobstructed line of sight between a positional sensor and a detector.
It is a further object of certain aspects of this invention to provide a localization system for internal anatomical structures which may be employed with minimal invasive procedures.
It is another object of certain aspects of this invention to provide an integrated anchor and localization sensor that may be deployed with relative ease.
It is yet another object of certain aspects of this invention to provide an anatomical anchor which may serve as both a preprocedural and intraprocedural fiducial marker.
It is an additional object of certain aspects of this invention to provide a reliable localization marker which may be placed in a patient in advance of a procedure and which may remain in the patient for a period of time following the procedure.
It is a further object of certain aspects of the present invention to enable movement detection, with five or six degrees of freedom, of an anatomical structure or surgical instrument (whether the instrument be an anchor, a catheter, or any other medical instrument).
These and other objects of the invention may be inherent or derived from the detailed description of the preferred embodiments.
The invention, in its broadest sense, may comprise one or more of the following aspects, either alone or in combination with one or more additional elements:
an anatomical anchor/sensor,
a receiver on an anchor for sensing signals generated external to the anchor,
a transmitter on an anchor for conveying signals indicative of the anchor""s location,
a signal generator on an anchor,
a connection for securing a receiver to an anatomical anchor,
a receiver and/or transmitter on a surgical screw, staple, pin rod, needle or soft tissue anchor,
an electromagnetic sensing coil on an anchor,
a magnet on an anchor,
an electromagnetic sensor having multiple collinear coils wound at differing angles, whether disposed on an anchor, a catheter, or other medical instrument,
hard-wiring a transmitter on an anchor to a processor,
affixing a wireless transmitter to an anchor,
affixing a conductive electrode to an anatomical anchor,
a surgical screw having a hollow containing a sensor,
affixing a sensor to anchor using potting material,
a sensor housing for the head of a screw,
an attachable/detachable sensor mount for an anchor,
a grasping region for permitting medical personnel to screw a portion of a screw/sensor into an anatomical structure,
an integrated anatomical anchor/sensor where the sensor is detachable,
methods and apparatuses for deploying an integrated anchor/sensor,
methods for making and using the above items,
procedures where the relative movement of instruments and/or anatomical structures are tracked and displayed, and
any other novel and unobvious aspects of the following disclosure and/or claims.